(a) Field of the Invention
The present invention provides an air gun firing system, which is able to employ a purely mechanical system to achieve a high speed continuous firing or single firing operation. The firing system uses a sliding shuttle tube able to move frontward and rearward between a bullet chamber and a cylinder. The sliding shuttle tube is subjected to a differential pressure variation of a pressure buffer chamber pressure source during the back-and-forth motion thereof, which changes the stroke direction of the sliding shuttle tube, and the accumulation and discharge operation causes the pressure of the pressure buffering chamber to be in a pulsed mode. The sliding shuttle tube is pushed outward when the pressure is high, and a returning arch force of an arch returning spring pushes the sliding shuttle tube back to its original position when the pressure is low. After repositioning, high pressure is again built up in the pressure buffer chamber, and the sliding shuttle tube is again propelled outward, thereby achieving a continuous back-and-forth striking motion. Furthermore, the speed of the back-and-forth movement is further subjected to an increase in the amount of air pressure in a prepositioned pressure regulating device of the pressure buffer chamber, thus enabling high-speed movement and achieving a high-speed firing operation. In addition, the intervention of a sliding retainer fitted to a trigger device enables restricting the system to a single firing operation.
(b) Description of the Prior Art
Pressurized air guns fire paint balls or BB balls during use thereof, and the source of the air pressure is compressed air. After regulating the pressure of the gun, an instantaneous high pressure enables firing of the bullet. There are two methods of firing, namely single firing and continuous firing. As for the continuous firing mode, this is commonly determined by electronic solenoid valve operation of an air blast. However, this solenoid valve is frequently subjected to change in pressure value of the pressure source, causing a change in the working condition and resulting in malfunction of the system. The reason for which is that when the valve body of the solenoid valve has the shape of a valve pin, and if the air pressure flowing through the solenoid valve is too large, then the surface of the valve pin driven by electromagnetic force will form different angled oblique force components. Furthermore, if the value of the force components is greater than the electromagnetic force, then movement of the suppressed valve pin is caused to fail. Moreover, the solenoid valve is used for the purpose of high speed firing, and, in general, the method used adopts a device fitted with a circuit board provided with a transistor switch, and the device is acted on by a relay circuit operated by the gun trigger to effect a trigger action, thereby enabling electronic switching elements to easily effect high frequency operation to achieve high speed firing of bullets. However, it is common for the circuit board to be often sold without warranty of parts. The reason for which is very simple, because the circuit board is unable to withstand mechanical vibration forces, and high-speed firing effects high-frequency movement which very easily damages the circuit board. Therefore, the circuit boards are also commonly seen as single units that are designed as kits which can be easily assembled to guns, thereby providing easy and rapid replacement and, because of the unfavorable affect of vibration on the circuit enable covering up a visible firing control device of the circuit board from the user. Hence, such a design is really not appropriate for use in high vibrating guns.
Moreover, the circuit needs a power supply to operate, and it is common for a user to forget to turn off the power supply after finishing their game activities, thereby causing the power supply to completely drain after the gun has been put away for about 3 to 5 days (varying depending on power consumption).
Related electronic control problems are really not suitable for actual needs, and many designs have abandoned the continuous firing operation, instead adopting a design whereby the finger is used to effect a pulling action on the trigger to effect a single shot operation, such as Gabrel's U.S. Pat. No. 8,033,276. In FIGS. 1, 12, 19, 21 of said patent, it can be seen that the firing operation drives a valve rod through a synchronous operation mode using a trigger, and uses axial displacement of the valve rod to change the high pressure airflow direction, which determines whether or not there is pressing on a plunger, thereby completing the firing operation. However, when the finger pulls the trigger, the action of the finger muscles are unable to meet the firing speed of a real gun, and is thus assisted with a design having a circuit board able to operate a solenoid valve at high frequency, which enables a pressure system to effect a firing operation at high frequency, as shown in FIGS. 9 and 36 of the patent.
Regarding the pressure accumulation time interval in the storage chamber of said patent, pressure is released after the cylinder is pushed out, forming a low-pressure space enabling an opportune shift-in of a valve portion therein, after which, because the position of the valve spool of the valve portion has changed, thus, the external portion of the gun is caused to channel in high-pressure air, and only then is the gun able to replenish the passageway. Moreover, the high-pressure device is disposed to match the storage chamber, thus, the design of the accumulated pressure operation of the storage chamber of said patent is such that the accumulated pressure time interval of the storage chamber is inevitably spent or occupied by the intervention of the valve portion during the stroke of the valve portion action. Hence, when using a high frequency firing control circuit configuration, the pulse frequency of the storage chamber is unable to keep up with the circuit board firing control frequency, and is unable to reach the tempo of continuous firing, or, because the pulse points and the operating points of the circuit controlling firing are not synchronized, even in a state whereby there is an elementary error in the time points, and under the conditions of an external pressure source maintaining a certain pressure value supply, the storage chamber still does not have the full likelihood of achieving an accumulated pressure state having the appropriate high value. thus causing a weakening of the firing pressure. The reason for which is because of the required time interval for the accumulated pressure, a portion being occupied by the working time of the action of the valve portion. Moreover, in order to prevent air admission and the opening-up of a ventilation action, because the structure of the valve portion causes the high-pressure air to flow from the outside into the path of the storage chamber and forms a critical time for an opening and closing action, both of which can occur in the flow path and the feedback pressure negatively affected by air flowing in different directions, thus, the required positive pressure is canceled out. At that time, an opposite acting force acts on the storage chamber through opening and closing of the valve portion, especially at the moment of the closing action, thereby enabling the nullified storage chamber to obtain the highest pressure value. Accordingly, it is difficult to meet the demands for a strong force and high-speed continuous firing.
Furthermore, in such a prior art design, it can be clearly seen that the accumulated pressure action of the storage chamber is necessarily acted on by the link rod directly joined to the trigger, or determined by whether or not the valve pin is indirectly hit out via a linkage operation through the operation of the circuit board, thereby changing the pressure airflow path through axial displacement of the valve pin and determining the firing action and accumulated pressure operation of the storage chamber. Hence, it is clear that if the trigger system is removed, then the valve pin forms a normally open state, under which conditions the storage chamber is then fixed in a continuously replenished state whereby the storage chamber continuously obtains pressure from an external pressure source (air cylinder). Accordingly, even if the cylinder of the storage chamber is pushed back to correspond therewith based on directional repositioning of a tension spring fitted on its circumference, the cylinder is again subjected to the pressure of the storage chamber and the external pressure source (which has not yet undergone pressurization) and further pushed out towards the firing direction. Although the cylinder at this time is seemingly effecting a continuous back-and-forth action, however, its displacement travel distance is extremely short, and is unable to travel a withdrawal distance sufficient to enable filling the space with bullets. Therefore, the storage chamber simply can not accumulate pressure, and thus does not have the required energy capacity for firing to occur.
Although the aforementioned removal trigger system is not suitable for a trigger operated gun firing simulation, however, if designed for guns with the requirement for continuous firing, then its is difficult for the system design of said patent to effect the capacity to realize such an operation.